The alleged offences are said to have taken place between 1968 and 1973.

Mr Napier, who is the half-brother of MP John Whittingdale, will appear at Westminster Magistrates Court in London on 2 September.

Baljit Ubhey, chief crown prosecutor for CPS London, said: "We have carefully considered the evidence gathered by the Metropolitan Police Service in relation to allegations concerning Charles Napier, a teacher at the time of the alleged offending between 1968 and 1973.

"Having completed our review, we have concluded there is sufficient evidence and it is in the public interest for Mr Napier to be charged with 21 offences of indecent assault."